Surgical needle-suture attachment possessing weakened suture segment for controlled suture release

Abstract

A combined surgical needle-suture device and a method for manufacturing the device employ a shrinkable tubing to connect the needle to a suture possessing a weakened segment. Separation of the needle from the suture is achieved by providing a weakened suture segment and applying a rupturing force to the suture within a predetermined range.

What is claimed is: 
     
       1. A method for attaching a surgical needle to a suture to provide a combined surgical needle-suture device which comprises: a) providing a surgical needle possessing a shank end of reduced cross-section and a suture possessing a weakened segment adjacent its tip region;   b) placing a shrinkable tubing around the reduced diameter shank end of the needle and the tip of the suture such that the weakened segment of the suture is positioned beyond, but proximate to, the tubing; and,   c) applying energy to the shrinkable tubing to bring the tubing into engagement with the needle shank and the tip of suture thereby providing the combined surgical needle-suture device.   
     
     
       2. The method of claim 1 wherein the weakened segment of the suture is obtained by irradiating the suture in the region of the segment with a suture-weakening dosage of radiation. 
     
     
       3. The method of claim 2 wherein the average force required to rupture the irradiation-weakened suture segment is within the following range for the suture indicated   ______________________________________                                    
              Average Rupture                                             
Suture Size   Force/Ounces                                                
______________________________________                                    
8/0           1-2                                                         
7/0           1-3                                                         
6/0           2-5                                                         
5/0           3-7                                                         
4/0            3-15                                                       
3/0            3-23                                                       
2/0            3-26                                                       
1/0           10-26                                                       
1             10-26                                                       
2 and larger   10-26.                                                     
______________________________________                                    
     
     
     
       4. The method of claim 2 wherein the suture is fabricated from a fiber-forming material selected from the group consisting of cellulose, cellulose ester, polyolefin, vinyl polymer, acrylic polymer, lactide homopolymer, lactide copolymer, glycolide polymer and glycolide copolymer. 
     
     
       5. The method of claim 1 wherein the suture is a monofilament suture. 
     
     
       6. The method of claim 1 wherein the suture is a braided suture. 
     
     
       7. The method of claim 1 wherein the weakened segment of the suture is obtained by forming a suture-weakening notch in the segment. 
     
     
       8. The method of claim 7 wherein the average rupture force required to rupture the notch-weakened suture segment is within the following range for the suture indicated   ______________________________________                                    
              Average Rupture                                             
Suture Size   Force/Ounces                                                
______________________________________                                    
8/0           1-2                                                         
7/0           1-3                                                         
6/0           2-5                                                         
5/0           3-7                                                         
4/0            3-15                                                       
3/0            3-23                                                       
2/0            3-26                                                       
1/0           10-26                                                       
1             10-26                                                       
2 and larger   10-26.                                                     
______________________________________                                    
     
     
     
       9. The method of claim 7 wherein the suture is fabricated from a fiber-forming material selected from the group consisting of collagen, silk, cotton, linen, nylon, polypropylene, polyethylene terephthalate, lactide homopolymer, lactide copolymer, glycolide homopolymer and glycolide copolymer. 
     
     
       10. The method of claim 1 wherein the shrinkable tubing is a memory metal or shrinkable plastic. 
     
     
       11. The method of claim 1 wherein the shrinkable tubing is a shrinkable polyvinylidene fluoride material. 
     
     
       12. The method of claim 1 wherein the step of applying energy further comprises applying energy to shrink the shrinkable tubing into engagement with the needle shank and thereafter applying energy to shrink the shrinkable tubing into engagement with the tip of the suture. 
     
     
       13. A combined surgical needle-suture device which comprises: a) a surgical needle possessing a shank end of reduced cross-section;   b) a suture possessing a weakened segment adjacent its tip region;   c) a shrinkable tubing around the reduced diameter shank end of the needle and the tip of the suture such that the weakened segment of the suture is positioned beyond, but proximate to the tubing;   the tubing being shrunk around the reduced diameter shank end of the needle and the tip region of the suture thereby providing the combined surgical needle-suture device.   
     
     
       14. The combined surgical needle-suture device of claim 13 wherein the weakened segment of the suture is obtained by irradiating the suture in the region of the segment with a suture-weakening dosage of radiation. 
     
     
       15. The combined surgical needle-suture device of claim 14 wherein the average force required to rupture the irradiation-weakened suture segment is within the following range for the suture indicated   ______________________________________                                    
              Average Rupture                                             
Suture Size   Force/Ounces                                                
______________________________________                                    
8/0           1-2                                                         
7/0           1-3                                                         
6/0           2-5                                                         
5/0           3-7                                                         
4/0            3-15                                                       
3/0            3-23                                                       
2/0            3-26                                                       
1/0           10-26                                                       
1             10-26                                                       
2 and larger   10-26.                                                     
______________________________________                                    
     
     
     
       16. The combined surgical needle-suture device of claim 14 wherein the suture is fabricated from a fiber-forming material selected from the group consisting of cellulose, cellulose ester, polyolefin, vinyl polymer, acrylic polymer, lactide homopolymer, lactide copolymer, glycolide polymer and glycolide copolymer. 
     
     
       17. The combined surgical needle-suture device of claim 13 wherein the suture is a monofilament suture. 
     
     
       18. The combined surgical needle-suture device of claim 13 wherein the suture is a braided suture. 
     
     
       19. The combined surgical needle-suture device of claim 13 wherein the weakened segment of the suture is obtained by forming a suture-weakening notch in the segment. 
     
     
       20. The combined surgical needle-suture device of claim 19 wherein the average rupture force required to rupture the notch-weakened suture segment is within the following range for the suture indicated   ______________________________________                                    
              Average Rupture                                             
Suture Size   Force/Ounces                                                
______________________________________                                    
8/0           1-2                                                         
7/0           1-3                                                         
6/0           2-5                                                         
5/0           3-7                                                         
4/0            3-15                                                       
3/0            3-23                                                       
2/0            3-26                                                       
1/0           10-26                                                       
1             10-26                                                       
2 and larger   10-26.                                                     
______________________________________                                    
     
     
     
       21. The combined surgical needle-suture device of claim 19 wherein the suture is fabricated from a fiber-forming material selected from the group consisting of collagen, silk, cotton, linen, nylon, polypropylene, polyethylene terephthalate, lactide homopolymer, lactide copolymer, glycolide homopolymer and glycolide copolymer. 
     
     
       22. The combined surgical needle-suture device of claim 13 wherein the shrinkable tubing is a memory metal or shrinkable plastic. 
     
     
       23. The combined surgical needle-suture device of claim 13 wherein the shrinkable tubing is a shrinkable polyvinylidene fluoride material. 
     
     
       24. The combined surgical needle-suture device of claim 13, wherein the shank end of the needle is provided with a texturized surface to facilitate gripping by said shrinkable tubing. 
     
     
       25. The combined surgical needle-suture device of claim 24, wherein the shank end of the needle is scored, ribbed or threaded, in whole or in part. 
     
     
       26. The combined surgical needle-suture device of claim 13, wherein said shank end of reduced cross-section forms a shoulder with a remainder of said needle. 
     
     
       27. The combined surgical needle-suture device of claim 26, wherein said shank end is tapered to expand in a direction away from said shoulder, such that a distal end thereof is of greater cross-sectional diameter than cross-sectional diameter in a region of said shoulder. 
     
     
       28. The combined surgical needle-suture device of claim 26, wherein said shank end is tapered to expand in a direction towards said shoulder, and that a distal end thereof is of smaller cross-sectional diameter than cross-sectional diameter in a region of said shoulder.